The ovarian cycle, follicular steroidogenesis and ovulation are exquisitely sensitive to a variety of external stimuli, including light-dark periods, nutrition, stress and a number of drugs, including marijuana and its active ingredients - tetra-hydrocannabinol (THC). Exposure to THC can temporarily halt the estrous cycle of the rat and can markedly reduce the number of ova shed on estrus. In this study, using in vivo and in vitro models, we will attempt to delineate indirect effects of THC mediated via the hypothalamus and pituitary, from possible direct effects of THC on the rat ovary and developing ovulatory follicles within it. Differences in structure, enzyme content, lysosome content and activity; and lipid and cholesterol content and structure will be examined in untreated ovaries and in ovaries which have been exposed, in vivo or in vitro, to various concentrations of THC. Differences in follicular structure will be studied using quantitiative electron microscopy. Differences in lipid and cholesterol usage will be examined using polarized light microscopy and various stains for lipid. Enzymes will be localized in frozen sections and enzyme activity measured using the scanning and integrating microdensitometer. Enzymes studied will include Delta 5-3Beta-hydroxysteroid dehydrogenase and glucose-6-phosphate dehydrogenase, two enzymes intimately involved in steroid production. The role of lysosomes in lipid transfer, and their relationship to cholesterol metabolism will be examined using quantitative cytochemical techniques. Lysosome number will be analyzed by localizing the lysosomal enzyme, acid phosphatase in frozen sections and in ultrathin sections of fixed material. It is hoped that these studies will provide a greater understanding of the possible effects of THC and/or marijuana on the female reproduction system.